ConditionInterface::condition docmentation contains wrong information

API page: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Database%...

Says "This method can take a variable number of parameters. If called with two parameters, they are taken as $field and $value with $operator having a value of IN if $value is an array and = otherwise."

That is no longer true because of the changes described in the change record Require a specific placeholder format in db_query() in order to trigger argument expansion, and require explicit 'IN' parameter for conditions

Specifically, IN is never assumed, and if you pass an array as the $value without specifying IN as the $operator you will get a database exception.